I took quilt classes 30 years ago and the instructor said to press the seams open. To align the seams when connecting blocks was to stick a pin in the first square right at the quarter inch from the edge then into the 2nd block. (Do not pin it in just stick it through the 2 blocks) Keep the pin straight up an down. With a 2nd pin, pin the 2 blocks together, but place the pin just in front of the 1st pin, You will use a 3rd pin which is used to pin a short distance after the 1st pin. As you sew, sew right up to the first pin, stop, take out the 1st pin, sew up to the 2nd pin and so on. This system has never failed me. I still use it today. Good Luck